Manitoba Hydro Transmission - Moving Power to Market
Manitoba Hydro's (MH) transmission network is comprised of 11,700 kilometres of transmission lines and 75,000 kilometres of distribution lines. The generating stations on the Lower Nelson River produce alternating current (AC) electricity. The AC electricity is converted (rectified) to direct current (DC) at stations in northern Manitoba and the DC electricity flows to the Winnipeg area on the HVdc transmission lines. At stations near Winnipeg the DC electricity is converted back to AC and the electricity is moved into Manitoba's transmission and distribution system. Lower voltage facilities are used to deliver electricity to distribution stations, and even lower voltages are used to deliver electricity to customers. Transformers are used throughout the electricity network to change the voltage levels.
MH's transmission facilities have been developed and are operated as an integrated system, with the backbone being two 800 kilometre, high voltage, direct current (HVdc) transmission lines (Bipole I and II). A third HVdc line (Bipole III) approximately 1,400 km in length is currently under construction. The initial HVdc lines (Bipole I and II) were located in a common transmission corridor and transmitted over 70 per cent of Manitoba Hydro’s annual energy production from its northern hydro stations on the Nelson River to southern load centres. Due to the reliance on one transmission corridor and a single station in southern Manitoba (Dorsey), the system is vulnerable to extensive power outages from fires or other extreme weather events or catastrophic failures. A new HVdc transmission line and new Riel converter station in southern Manitoba are being constructed to reduce dependency on the Dorsey Station and the existing HVdc Interlake corridor to assure the reliability of power to Manitobans.
More widely, new interconnection capacity to electricity markets increases both the reliability of Manitoba's own system, as well as Manitoba's reach into export markets. MH exports electricity to Ontario, Saskatchewan and the US. Most of the MH's export market is to the U.S. MH exports electricity to Ontario, Saskatchewan and the US. Most of the MH's export market is to the U.S.
